Copolymers of vinyl isocoumarans with 1,3-dienes and process for obtaining same



Patented June 28,1949

COPOLYMERS OF VINYL ISOCOUMABANS WITH 1,3-DIENES AND PROCESS FOR OB-TAINING SAME Arthur 1.. Barney, Wilmington. Del., auignor to i E. I. duPont de Nemours a Company, Wilmington, Del., a corporation of DelawareNo Drawing. Application September 19, 1946,

- Serial No. 97,902

12 Claims. (01. 260-865) This invention relates to new and usefulcompositions 01 matter, and more particularly to polymeric materials.

This invention has as an object a class of polymeric materialscomprising new copolymers which are characterized by improved tensileproperties, and which are of particular value in the coating, moldingand textile arts. Further objects reside in methods for obtaining thesecopolymers. Other objects will appear hereinafter.

The above objects are accomplished by copolymerizing at moderatetemperature and in contact with a polymerization catalyst a mixture ofcertain vinyl isocoumarans which are defined below, and particularly1,3-alkyl-4- vinylisocoumarans, with a 1,3 diene.

The above mentioned vinyl isocoumarans have the formula en EH:

wherein the two valences of each of carbon atoms at positions 1 and 3are satisfied by substituents selected from the group consisting ofhydrogen and hydrocarbon radicals consisting of monovalent alkylradicals, monovalent aryl radicals, and divalent polymethylene radicalshaving a chain of four to five carbon atoms, not more than one of saidsubstituents being hydrogen, the valences of carbon atoms at positions 1and 3, when satisfied by a polymethylene radical, being attached totheterminal carbon atoms of a divalent polymethylene radical having a chainof four to five carbon atoms to form a polymethylene ring of five to sixcarbon atoms.

The present copolymers are obtainedby reacting a mixture ofpolymerizable materials consisting wholly or preponderately of thosedefined above at a temperature of from about C. to 200 C. in contactwith apolymerization catalyst. The reaction is best carried out bycontacting a mixture or the vinyl isocoumaran and a 1,3-diene with from0.25 to 1.0% of aperoxygen compound 2 such as potassium persuliate,based on the total weight or the monomers employed, and a suitablemedium such as water, or in conjunction with water insoluble catalystsuch as benzoyl peroxide, an organic solvent such as benzene. Whenemploying an aqueous system, it is advantageous to use any of a numberor commonly used emulsifying agents such as sodium oleate, and otheremulsifying aids such as sodium dinaphthyl methane sulionate, to aid inthe proper dispersion of the monomers. In addition,

it is preferred to employ 0.01 to 0.5%.01 an auxiliary catalyst such aspotassium i'errlcyanidein conjunction with water soluble catalysts suchas potassium per-sulfate... Other adjuvants, such as dodecyl mercaptan,commonlyutilized as polymerization control agents may be employed asdesired. The reaction medium, whether aqueous or non-aqueous, is not anessential constituent of the reaction mixture, but I prefer to employone to aid in the proper mixing and dispersing of the monomers andcatalyst with one another. The reaction may be carried out. however,without the inclusion of water and dispersing agent,

or an organic solvent in thereaction mixture. The reaction may be run ina closed system or additional monomer or monomers may be injected fromtime to time as desired. The following examples in which the parts givenare by weight, illustrate ways in which the invention may be practiced.

Example I ionate, 0.5 part or potassium persulfate and 300- parts ofcopper-free distilled water, and the reaction mixture agitated for 16hours at 50 C.

The product, after cooling and opening the re-- action vessel, iscoagulated with an aqueous 10% acetic acid solution and brine, washedand dried by milling. There is obtained 98.5 parts of nervy,

tough polymer. The rubber so prepared, when compounded with 2.0 parts ofsulfur, 50 parts of a medium processing channel black, 2.0 parts ofstearic acid, 5.0 parts of zinc oxide and 1.25-

parts or 2-mercaptothiazoline, and cured for 45 minutes at 141"-C.,possesses astress-strain value at 25 C. of 1280 p; s. i. at 300%elongation.

Etample II There is added to asuitable vessel, '75 parts oi butadiene,25 parts of l,'l,3,3-tetramethyl-4-vinylisocoumaran, parts of soarr, 0.3part of potassium persulfate, 0.5 part of dodecyl mercaptanand 185 parts"of copper-free distilled water, and I the reaction mixture agitatedfor- 16'hours at 50 C. The product,'after cooling and opening thereaction vessel,j-is stabilized with 5 parts of adispersionof a 55:45-mixture of phenyl-alpha-' dime-1,3, 2,3-dichlorobutadiene-1,3,2-fluorobutadiene-1,3 and the like; alkoxy-l,3-but adienes.

such as 2-methoxybutadiene-l,3, 2-phenoxybutadime-1,3,- and the. like;and cyanoprenes such as 2-cyanobutadiene-L3.

methyl. thyl. 'P OPYL isoamyl,. hexyl; methylene, phenyl", tolyl, and"x'yly other amples oi the vinyl isocoumarans useful in the a r practiceof this invention are 1,3-dlmethyl-4-vlnnaphthylamln'e'anddiphenylamine, Icoagulated with an aqueous 10%- acetic acid solution andbrine, washed'and driedby milling. There is ob-" tained 92;parts of aslightly tacky, rubber-likev polymer. The rubber s0 prepared, when com-3 pounded'wlth 2.0 parts of suliur, 50 parts 01' a medium processingchannel black,,2,0 parts of I stearic acid, 5.0 parts of-zinc oxide and1.25 parts of z-mercaptothiazoline, and cured ior30 minutes at 1530,..possesses a stress-strainvalue at C. of 3220 p; s; i. at 430%elongation as compared to a stress-strain value; 01 1240 p. s; i. at340% elongation for a similarly compoundedrubber usmay p lybutadieneinstead of the vinylisocoumaran/butadiene copolymer described above.

. ,Ezample II! I There is added to a suitable vessel, 75"parts ofbutadiene, 25parts oi. 1,1,3,3-tetramethyl-4-vinylisocoumaran; 4.0 partsof oleic acid, 1.07 parts: of sodium hydroxide, 1.0 part of thedispersing agent mentioned in Example -I, 1.0 part of potassiumpersulfate, 0.15 part of potassium i'erricyanide, 0.5 part of dodecylmercaptan and 150 parts of copper-freedistilled water, and the reactionmixture agitated for 16 hours at 50 C. The product, after cooling andopening the reaction vessel, is sta bilizedwith5- parts ofa dispersionof a 55:45 mixture .of phenyl-alpha- -naphthylamine anddiphenylamine,zcoagulated with an aqueous 10%. aceticiacid solution andbrine, washed and dried by jnulling. There is obtained 103 parts of aslightly tacky, rubber-like polymer. The rubberso 2'5 viously mentionedrangedepend on the polymer- ,ylisocoumar'an,,3Fdimethyl-l,3-diethyl-4-vinylisocoumaran, 1,3dimethyl-1,3-dipropyl-4winylisocoumaran, -l',3-'dipentamethyiene 4vinylisocoumaran, .[4'1vinyldispiro-(cyclohexane- 1,'1'--isocoumaran-Zi' lf'cyclohexane) 1,3-dimethyl-.

l,3-diphenyl 4-vinylisocoumaran,-, 1 1,3-dimethyll,3-di(p-tolyl)-4vinylisocoumaran and the like.

The vinyl-'isocouma-rans-most advantageously used in the practice ofthis invention are those in which the hydrocarbon radicals in the 1,3-

positions contain from 1 tot carbon atoms, preferably alkyl. 1 I f g Thetemperature employed within the preizing characteristicsjof theparticular unsaturated compound which is to be polymerized. In"

1 ize 'atja satisfactory rate and in such general, however. thepreferred. range of temperature is from about 30 C. to about 75 6.,since within this rangejhe. above compounds polymerupper pressure limitdepending only on the appaprepared, whencompounded with 2.0 parts ofsillfur, .parts of Micronex, 2.0 parts of stearic acid, 5.0 ,partsofzincoxideand 1.25 parts of '2-mercapto-thiazoline, and curedior 30minutes at 153 0., possesses a stress-strain value at 25 C. of 3080 5 p.5.1. at'400% elongation. 7 l,

' ExampleIl/f There is added to a suitable reaction vessel 75 parts ofchloroprene, 25 parts of l,1,3,3-tetra'- methyl-4-vinylisocoumaran, 4.0parts of rosin, 0.9 part of sodium hydroxide, 0.7 part of the dispersingagent mentioned in Example I, 0.4 part of potassium persulfate, 0.2 partof dodecyl mercaptan and 137 parts of copper-free distilled water, andthe reaction mixture agitated for 4 hoursat 40 C. The product, aftercooling and opening the reaction vessel, is stabilized with 5 includehydrocarbons such as hexane, octane,

ratus available. In general, however, I prefer for reasons ofconvenience to arry out the polymerization at ordinary or auiogenouspressures.

. The use of water, or an organic solvent, is not.

an essential feature of the invention. However, .in most cases, the useof water or an inert organic solvent is desirable to aid in the propermixing and dispersingof catalyst "and monomers. Ex-.

amples 'of inert organic solvents which may be employed,instead of, orin addition to water,

isooctane, cyclohexane, methylcyclohexanes, ben- 0 zene. toluene andxylenes, alcohols such as tertiary'butanol, others such as diethyl etherand 'dioxane, esters such as ethyl acetate and ethyl benzoate, alkyl andaryl: halides such as carbon tetrachloride, chloroform, ethylenedichloride, ethyl chloride and chlorobenzene, ketones such as acetoneand cylohexanone', nitriles such as acetonitrile and benzonitrile, andthe like. It is pre-,.

dime-1,3, isoprene, piperylene and the like: halo gen-substituted1,3-buta'dienes such as 2-chlorobutadiene-L3, 2-bromobutadiene-1,3,2-iodobutaferred-to employ a dispersing agent, and other emulsifyingaids such as Daxad-ll (sodiu'm dinaphthyl methanesulfonate), to aid inthe proper mixing and dispersing of-water insoluble catalyst andmonomers in aqueous systems. Any

.of a number of dispersingagents commonly employed in emulsionpolymerizations may be used such as those containingas the activeingredients the sodium salts 'of'higher alkyl-sulfates such as sodiumdecyl, dodecyl andtetraidccyl sulfates;

the sodium salts of 'higher' 'alkane sulfonates such" as sodium decyland dodecyl' sulfonates; the

nionosodium salt ofsuli'ated methyl oleate; the sodium saltof'sulfonated oleyl acetate; sodium oleate: sodlum'rosinate and thelike.

Afjwide' variety of polymerization catalystss'may I be employed in thepractice of this invention. Among the most useful of these catalysts area fashion that-the reaction is readily'controllabla The process of thisinvention maybe carriedout under pressures varying from atmospheric orautogenous to 1000 atmospheres or higher, the

bis (alpha methylbutyronitrile) a those compounds capable of initiatingpolymerization such as tree radical generating materials represented byperoxygen and azo compounds, and inorganic acids and their metal salts.By per-oxygen compounds is meant a compound containing the peroxygenlinkage. -OO-; and by azo compounds is meant a compound containing theazo linkage, -N=N. As examples, there may be mentioned: peroxygencompounds such as di-acyl peroxides including di-benmyl peroxide,benzoyl acetyl peroxide, -di-lauroyl peroxide, di-acetyl peroxide anddi-propionyl peroxide, di-alkyl peroxides including di-ethyl peroxide,dipropyl peroxide and di-(tertiary butyl) peroxide, hydrogen peroxide,inorganic peroxides including barium peroxide, magnesium peroxide andzinc. peroxide, and salts of non-metallic inorganic peroxygen acidsincluding ammonium persulfate, potassium persulfate, so-

dium persulfate, potassium percarbonate, potassium perphosphate andsodium perborate, the

V salts or peroxygen acids being especially eflective if used inconjunction withminorproportions of an auxiliary catalyst such as sodiumbisulfite,

sodium hydrosulfite, potassium ferricyanide, etc.; azo compounds such asalpha,alpha'-azobis- (alpha,gamma-dimethylvaleronitrile), dimethyl anddiethyl alpha,alpha'-azodiisobutyrate, 1,1-azodicyclohexanecarbonitrile, alpha,alpha-azoalpha,alpha'-azobis(alpha-ethylbutyronitrile) and alpha,alpha-azobisdiisobutyrocarbonamide; and in- 6 scribed in ChemicalAbstracts, 3'1, 2343 (.1943), and Chemical Abstracts, 39, 1619 (1945).For example, 1,1,3,3-tetramethyl-4-vinylisocoumaran can be readilyprepared by the self-condensation of dimethyl(vinylethinyl) carbinolCHa=CH-C E C-C (CH3) H which in turn can be obtained from monovinylthemanufacture of a large number of improved articles of manufacture. Forexample, when compounded and vulcanized in the usual manner, thesecompositions can be made into many useful articles of commerce, such astires, tubing, massive articles, tapes for electrical applications, etc.

:When compounded and vulcanized in the usual ,manner, films andintricately shaped articles such as gloves, balloons and other hollowarticles can be prepared from the latex by coagulation employing wellknown methods of straight dip,

coagulating dip or porous-cup processes.

As many apparently widely different embodi ments of this invention maybe made without organic acids and their metal salts such as sulfuricacid, phosphoric acid, aluminum chloride, zinc chloride, borontrichloride boron triiiuoride and the like. The catalyst should beemployed in an amount in excess of 0.001% (based on the total weight ofmonomers), and preferably, there is employed between 0.1 and 1.0% ofcatalyst.

other adjuvants, such as dodecyl mercaptan,

dialkyl xanthogeno sulfides and the like, commonly utilized aspolymerization control agents may be employed as desired.

A small amount of the vinyl isocoumaran relative to the 1,3-diene yieldsproducts having properties and utility quite diiierent from the polymerobtained by polymerizing either of these components alone. Thus thecopolymer of Example II containing 25% of the vinyl isocoumaran and 7 5oi butadiene-l,3, when compounded into a tread stock has much greatertensile strength than a similarly compounded polybutadiene. The mostuseful copolymers are those containing on the basis of the weight of thecopolymer from 5 parts of the vinyl isocoumara'n and 95 parts of the1,3-diene compound to 50 parts of the vinyl isocoumaran and 50 parts ofthe 1,3-diene compound. However, eopolymers which differ appreciablyfrom the separately polymerized components are obtained within the rangeof from 99 partsoi the vinyl isocoumaran and 1 part of the 1,3-dienecompound to 1 part of the vinyl isocoumaran and 99 parts of the1,3-diene compound. Of particular utility are the copolymers containingfrom 20% to 40% of the vinyl isocoumaran based on the combined weight ofthe diene and the vinyl isocoumaran. These copolymers, as compared tothose prepared from other proportions of these compounds and to thepolymer obtained from either ingredient alone, exhibit a marked increasein tensile strength.

The vinyl isocoumarans used in the practice of the present invention arebest prepared by the self-condensation of the corresponding(vinylethinyl) carbinol according to the method dedeparting from thespirit and scope thereof, it is to be understood that I do not limitmyself to the specific embodiments thereof except as defined in theappended claims.

I claim:

1. A copolymer comprising the copolymerization product of avinyl'isocoumaran and a 1,3- diene, said co-polymer containing, byweight of said vinyl isocoumaran and said diene from 5%,- to of saidvinyl isocoumaran, said vinyl isocoumaran being of the formula whensatisfied by a polymethylene radical, being attached to the terminalcarbon atoms of a divalent polymethylene radical having a chain of fourto five carbon atoms to form a polymethylene ring of five to six; carbonatoms.

2. The copolymer defined in claim 1 in which one valence of each carbonatom in positions 1 and 3 in said vinyl isocoumaran is satisfied by analkyl radical containing from 1 to 6 carbon atoms.

3. The copolymer defined in claim 1 in which said diene is a1,3-butadiene hydrocarbon.

4. The copolymer defined in claim 1 in which said diene is a halogensubstituted 1,3-butadiene.

5. Thelcopolymer defined in claim 1 in which all the valences on eachcarbon in positions 1 and 3 in said vinyl isocoumaran are satisfied byCH3.

said diene is butadiene.

'l. The copolymer defined in claim 5 in which said diene is chloroprene.

8. A process for obtaining copolymers which comprises reacting, in thepresence of a polymerization catalyst at a'temperature of from 10 C. to200 C. and under a pressure of at least atmospheric, 9, vinylisocoumaran and a LSI-diene, said vinyl isocoumaran being present inamount of 5% to 95% by weight of said 1,3-diene and said vinylisocoumaran, said vinyl isocoumaran being ofthe formula p valent aikylradicals. monovalent aryl radicals, and divalent polymethylene radicalshaving a chain of four to five carbon atoms, not more than one 01' saidsubstituents being hydrogen, the" valences or carbon atoms at positions1 and 3, when satisfied by a polymethylene radical, being attached tothe terminal carbon atoms or a divalent polymethylene radical having achain of four to five carbon atoms to form a polymethylene ring of fiveto-six carbon atoms. i

1 9. The process set forth in claim 8 in which one valence of eachcarbon atom in positions 1 and 3m said vinyl isocoumaran is satisfied byan alkyl radical containing from 1 to 6 carbon atoms.

10. The process set forth in claim 8 in which all the valences of eachcarbon atom in positions 1 and 3 in said'yinyl isocoumaran are satisfiedby CH1."

11. The process set forth in claim 10 in which said dieneisbutadiene.

wherein the two valences of each of carbon atoms at positions 1 and 3are satisfied by snbsti'tuents selected from the group consisting ofhydrogen and hydrocarbon radicals consisting of 'mono-' 12. The processset .forth in claim 10in which said di'ene is chloroprene.

, No references cited.

